The water Surface Profile reports the results of the hydraulic calculations graphed in the culvert. The Culvert dimensions are superimposed onto a graph with distance along the x-axis and elevation along the y-axis.   

The following variables are displayed:

·         Water Level

Water level in the culvert modeled using gradually varied flow calculations.

·         Critical Depth

Depth at critical flow is the transition or control flow that represents the minimum energy in the flow with the maximum discharge for that depth. Theoretically it represents the minimum depth that water can flow through a culvert or over a boulder, log or weir.

See also: Froude Number and Flow States

·         Normal Depth

Normal depth is the depth of flow in a channel or culvert when the slope of the water surface and channel bottom are the same and the water depth remains constant. Normal depth only applies to the condition of uniform flow.

See Also: Defining Normal Depth,  Manning's Equation

·   Headwater Elevation

The headwater elevation is the water surface elevation immediately upstream of the culvert.

See Headwater Calculations for details.

·         Tailwater Elevation

The tailwater elevation is the water surface elevation immediately downstream of the culvert outlet. In most cases the tailwater elevation is a function of the flow as determined in the Tailwater Methods section of the input window.

See also: Tailwater Methods,  Tailwater Control

·         Outlet Pool Bottom

The outlet pool bottom is an input variable usually the result of a field survey. This will determine the depth of the pool and is used in leap calculations.

See also: Minimum Plunge Pool Depth Calculations